SHUTTERING: Low carbon concrete Structures witH aUxeTic TextilE foRmworks as reinforcING element

Current methods of concrete construction seldom utilise the fluidity of concrete to create optimised, complex structural forms. Instead, they rely on rigid, flat, impermeable formwork to create solid, prismatic, unoptimized shapes that have poor material efficiency and consequently a large carbon footprint that is further worsened by the use of Portland cement (PC), the production of which is responsible for ~8% of worldwide CO2 emissions. We aim to address these critical limitations in formwork and cement, which not only promote material inefficiency and increase embodied carbon but also shackle creativity in design with structural concrete.

SHUTTERING will develop a novel, transformative approach to concrete construction based on (i) dual-purpose auxetic textiles that serve initially as formwork - to cast concrete into creative, optimal geometries that use concrete only where it is required, and then as reinforcement - offering stiffness and strength to the structure post-hardening; and (ii) low carbon concrete based on alkali activated binders that can be sourced from industrial waste streams and have the potential to reduce embodied carbon by 70% in comparison to ordinary Portland cement.

The novel concepts developed in this project will give a significant impetus to sustainable manufacturing in the construction sector as they will:
- improve material utilisation efficiency greatly - by using concrete only where needed;
- speed up construction process - by eliminating need for de-moulding and using AAB cement;
- avoid steel reinforcement - thus eliminating corrosion risk and reducing embodied energy, as well as avoiding the time-consuming task of preparing the reinforcement steel cages;
- increase structural performance - due to the inherent confinement effects of textile formwork (casing), further augmented by the negative Poisson's ratio of the auxetics;
- promote circular economy - since AAB use by-products from several industrial processes.

Outcomes of the projects will enable novel intelligent functionalities of concrete structural elements for IoT applications, such as diffuse fibre-based sensing devices for the structural health monitoring, and will pave the road towards complex shapes for the assembly/disassembly of structural elements, making the reuse of concrete structure a reality. Results will also foster radically new approaches for aesthetical finishing of concrete elements, in term of colour, texture, and engraved graphics.
Other applications of the materials developed in this project can be predicted in the field of structural retrofitting of existing concrete structures using auxetic textiles.